1. Technical Field
The present invention generally relates to a computer comprising a storage function for storing data of a storage device, and particularly relates to a computer comprising a data replication function or remote copy function (hereinafter referred to as the “remote copy function”) for transferring data of the storage device to an external storage controller.
2. Description of the Related Art
A client-use computer such as a personal computer to be used by a user for running application programs such as document processing is basically configured the same as a server-use computer such as a web server or an email server that executes application programs for providing service to a plurality of users, and is configured from computer resources such as a CPU, a memory, a hard disk, a network connection and the like.
A client-use computer generally has limited computational resources in comparison to a server-use computer. In addition, when the client-use computer is a portable computer such as a laptop (notebook) computer, there are many cases where the client-use computer is subject to physical shock and damaged while it is being carried around.
A computer stores an operating system, application programs and user data in a storage device such as a hard disk, and the operating system reads application programs and user data from the storage device into a memory, updates the user data and the like, and writes the same into the storage device according to instructions from the user.
As technology for preserving this kind of data, for example, RAID (Redundant Arrays of Inexpensive Disks) technology for collectively managing a plurality of hard disks as a single hard disk is well known, and it is primarily implemented in a server-use computer.
In light of the failure rate of client-use computers, it is also necessary to take measures for reliably preserving data as with server-use computers, but since the foregoing RAID technology requires a plurality of hard disks, it is inappropriate for use in client-use computers with limited computational resources.
Thus, technology has been disclosed for using a bitmap table corresponding to the data area of a storage apparatus and transferring the data of a first storage to a second storage (e.g., US Patent Application Publication No. 2005/0071589).
Also disclosed is technology of acquiring write data from a first storage and transferring such write data to a second storage (e.g., US Patent Application Publication No. 2004/0078630)